The invention is particularly illustrated in relation to flagellate parasites, such as Histomonas meleagridis and Trichomonas vaginalis although it can apply to any flagellate parasite the structure and physiology of which is similar to that of the above-mentioned parasites belonging to the phylum Metamonada.
The parasite Histomonas meleagridis is responsible for an infectious parasitic disease of galliform birds called histomoniasis. This disease is a typhlohepatitis particularly infecting turkeys. It appears as a sulphur-yellow diarrhea often leading to high mortality. Cyanosis observed in the fleshy appendages of the head has given this disease the name of blackhead disease. Other clinical symptoms are feathers spotted with droppings, anorexia, drowsiness, abnormal gait, the head held low or hidden under a wing. Considerable mortality is seen from the 14th day. Without treatment, more than 90% of the animals may die. Surviving galliform bird, in particular turkeys, show delayed growth relative to clinically unaffected birds.
Many different treatments have already been suggested to counter histomoniasis: the nitroimidazoles in particular, especially dimetridazole (DMZ), are very active against Histomonas meleagridis. However, because of their toxicity for consumers, this family of molecules has been withdrawn from the market. Albendazole and the other benzimidazoles proved to be ineffective in treating histomoniasis. The same applies to the other antibiotics currently authorised for sale, as well as to anticoccidial drugs such as roxarsone. Moreover, immunisation trials with attenuated strains have never worked.
Given this situation, the only conceivable prophylaxis consists of either separating the species or administering an effective anthelminthic against the protozoa.
In other words, the invention proposes to solve the problem of producing an effective formulation for prophylactic and curative treatment, particularly in galliform birds, of the protozoan Histomonas meleagridis. 
The invention is also more particularly illustrated in relation to a flagellated protozoan Trichomonas vaginalis with physiology and structure similar to that of Histomonas meleagridis. Trichomonas vaginalis is a flagellated protozoan which develops in humans essentially localised in the urogenital region. It leads to an ubiquitous sexually transmitted disease known as trichommoniasis.
In women, clinical symptoms present as acute vulvo-vaginitis with a continuous frothy foul-smelling greenish yellow leucorrhoea, or valvular pruritus with a burning sensation. Complications are cervical neoplasia and premature delivery.
In men, trichommoniasis is asymptomatic and this contributes to the spread of the disease. Urethritis, epididymitis, prostatitis and even sterility can occur.
The products currently prescribed belong to the imidazole family, particularly metronidazole, ornidazole, secnidazole, tenonitrozole, and tinidazole. While effective, these products must be used with some care, in particular in pregnant or breast-feeding women.
In general terms, the problem to be solved is thus to produce a formulation which is effective for the prophylaxis and treatment of human or animal diseases involving flagellated protozoa, in particular Histomonas meleagridis and Trichomonas vaginalis, which, in addition, is neither cytotoxic nor mutagenic.
Surprisingly, the applicant has found and demonstrated that fenugreek has parasiticidal or parasitostatic properties as far as the previously mentioned protozoa are concerned and more generally concerning all flagellated protozoa belonging to the Metamonada phylum which have a similar structure and physiology to that of Histomonas meleagridis and Trichomonas vaginalis. 
The document JP 2008011731 describes a formulation containing a fenugreek extract intended to treat diarrhea in piglets. The document FR-A-2 833 813 describes a formulation containing a fenugreek extract intended to treat coccidiosis.